The present invention is generally directed to micro and nano-sized particles formed of semiconductor compounds, thermoelectric compositions formed of such particles, and methods for their synthesis.
Group IV-VI binary semiconductor materials are currently of interest for use in thermoelectric applications, such as power generation and cooling. For example, PbTe-based compounds can be used in solid-state thermoelectric (TE) cooling and electrical power generation devices. A frequently utilized thermo-electric figure-of-merit of a thermoelectric device is defined as
      Z    =                            S          2                ⁢        σ            k        ,where S is the Seebeck coefficient, σ is the electrical conductivity, and k is thermal conductivity. In some cases, a dimensionless figure-of-merit (ZT) is employed, where T can be an average temperature of the hot and cold sides of the device. It has also been suggested that nanostructured materials can provide improvements in a thermoelectric figure-of-merit of compositions incorporating them.
Accordingly, there is a need for methods of synthesizing nanostructured semiconductors from Group IV-VI materials. There is also a need for such synthetic methods that provide high yields and can be readily implemented. Moreover, there is a need for improved IV-VI micro and nanostructures that would exhibit enhanced thermoelectric properties.